FIVN · Five9, Inc.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 2, 2025.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $35.00 to $35.16, inclusive. The reporting person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 3, 2025.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 2, 2025.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 2, 2025.

The reported sales were to cover taxes upon the vesting of restricted stock units.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $24.63 to $25.62, inclusive. The reporting person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The reported sales were to cover taxes upon the vesting of restricted stock units. The sales reported in this Form 4 were effected in accordance with Five9, Inc.s previously established sell to cover withholding policy, the Corporations Policy.

The price reported in Column 4 is a weighted average price applied to the transaction by the broker under the Corporations Policy for sales to cover taxes upon vesting of restricted stock units for all individuals, including the reporting person subject to the Corporations Policy on the date such sales occurred. The reporting person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

The sale reported on this form represents a Five9, Inc. mandated sale by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units, and it does not represent a discretionary trade by the Reporting Person.

The price reported in Column 4 is a weighted average price applied to the transaction by the broker for sales to cover taxes upon vesting of restricted stock units for all employees of Five9, Inc., including the Reporting Person, on the date such sales occurred. The Reporting Person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 3, 2025.

The reported sales were to cover taxes upon the vesting of restricted stock units.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $24.62 to $25.62, inclusive. The reporting person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 2, 2025.

The reported sales were to cover taxes upon the vesting of restricted stock units.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $23.58 to $24.55, inclusive. The reporting person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 2, 2025.

The reported sales were to cover taxes upon the vesting of restricted stock units.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.65 to $25.83, inclusive. The reporting person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 3, 2025.

The reported sales were to cover taxes upon the vesting of restricted stock units.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $23.60 to $24.60, inclusive. The reporting person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The sale reported on this form represents a Five9, Inc. mandated sale by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units, and it does not represent a discretionary trade by the Reporting Person.

The price reported in Column 4 is a weighted average price applied to the transaction by the broker for sales to cover taxes upon vesting of restricted stock units for all employees of Five9, Inc., including the Reporting Person, on the date such sales occurred. The Reporting Person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

The reported sales were to cover taxes upon the vesting of restricted stock units. The sales reported in this Form 4 were effected in accordance with Five9, Inc.s previously established sell to cover withholding policy, the Corporations Policy.

The price reported in Column 4 is a weighted average price applied to the transaction by the broker under the Corporations Policy for sales to cover taxes upon vesting of restricted stock units for all individuals, including the reporting person subject to the Corporations Policy on the date such sales occurred. The reporting person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 3, 2025.

The reported sales were to cover taxes upon the vesting of restricted stock units.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.64 to $25.83, inclusive. The reporting person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The sale reported on this form represents a Five9, Inc. mandated sale by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units, and it does not represent a discretionary trade by the Reporting Person.

The price reported in Column 4 is a weighted average price applied to the transaction by the broker for sales to cover taxes upon vesting of restricted stock units for all employees of Five9, Inc., including the Reporting Person, on the date such sales occurred. The Reporting Person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

The sale reported on this form represents a Five9, Inc. mandated sale by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units, and it does not represent a discretionary trade by the Reporting Person.

The price reported in Column 4 is a weighted average price applied to the transaction by the broker for sales to cover taxes upon vesting of restricted stock units for all employees of Five9, Inc., including the Reporting Person, on the date such sales occurred. The Reporting Person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

On May 20, 2026, Five9, Inc. (the "Issuer") granted a total of 8,972 restricted stock units ("RSUs") of the Issuer to Sagar Gupta, a member of the Issuer's board of directors (the "Board") in respect of his service on the Board. Mr. Gupta holds these RSUs for the benefit of certain investment funds (the "Anson Funds") for which Anson Advisors Inc. and AnsonFunds Management LP serve as co-investment advisors. Each RSU represents a contingent right to receive one share of Common Stock. The RSUs will vest on the one-year anniversary of the grant date, or immediately prior to the Company's next annual meeting of the Company's stockholders at which directors are regularly elected.

Because Mr. Gupta serves on the Board as a representative of the Anson Funds, Mr. Gupta does not have a right to any economic interest in securities of the Issuer granted to him by the Issuer in respect of his Board position. The Anson Funds are entitled to receive all of the economic interest in securities granted to Mr. Gupta by the Issuer in respect of Mr. Gupta's Board position. Mr. Gupta disclaims beneficial ownership of the Issuer's securities to which this report relates and at no time has Mr. Gupta had any economic interest in such securities except any indirect economic interest through Anson Funds, entities in which he does not have a controlling interest and over which he does not have investment control.

As discussed in footnotes 1 and 2, represents securities in which the Anson Funds have all of the economic interest.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $20.97 to $21.10, inclusive. The reporting person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $21.20 to $21.22, inclusive. The reporting person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 3, 2025.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 3, 2025.

The sale reported on this form represents a Five9, Inc. mandated sale by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units, and it does not represent a discretionary trade by the Reporting Person.

The price reported in Column 4 is a weighted average price applied to the transaction by the broker for sales to cover taxes upon vesting of restricted stock units for all employees of Five9, Inc., including the Reporting Person, on the date such sales occurred. The Reporting Person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on May 14, 2025.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $17.92 to $18.07, inclusive. The reporting person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The sale reported on this form represents a Five9, Inc. mandated sale by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units, and it does not represent a discretionary trade by the Reporting Person

The price reported in Column 4 is a weighted average price applied to the transaction by the broker for sales to cover taxes upon vesting of restricted stock units for all employees of Five9, Inc., including the Reporting Person, on the date such sales occurred. The Reporting Person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 3, 2025.

The reported sales were to cover taxes upon the vesting of restricted stock units.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $17.46 to $17.96, inclusive. The reporting person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on May 14, 2025.

The reported sales were to cover taxes upon the vesting of restricted stock units.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $17.49 to $17.92, inclusive. The reporting person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 3, 2025.

The reported sales were to cover taxes upon the vesting of restricted stock units.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $17.43 to $17.99, inclusive. The reporting person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The sale reported on this form represents a Five9, Inc. mandated sale by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units, and it does not represent a discretionary trade by the Reporting Person.

The price reported in Column 4 is a weighted average price applied to the transaction by the broker for sales to cover taxes upon vesting of restricted stock units for all employees of Five9, Inc., including the Reporting Person, on the date such sales occurred. The Reporting Person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

The option granted on March 9, 2016 is fully vested.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 10, 2024.

The sale reported on this form represents a Five9, Inc. mandated sale by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units, and it does not represent a discretionary trade by the Reporting Person.

The price reported in Column 4 is a weighted average price applied to the transaction by the broker for sales to cover taxes upon vesting of restricted stock units for all employees of Five9, Inc., including the Reporting Person, on the date such sales occurred. The Reporting Person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

The sale reported on this form represents a Five9, Inc. mandated sale by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units, and it does not represent a discretionary trade by the Reporting Person.

The price reported in Column 4 is a weighted average price applied to the transaction by the broker for sales to cover taxes upon vesting of restricted stock units for all employees of Five9, Inc., including the Reporting Person, on the date such sales occurred. The Reporting Person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

The sale reported on this form represents a Five9, Inc. mandated sale by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of restricted stock units, and it does not represent a discretionary trade by the Reporting Person.

The price reported in Column 4 is a weighted average price applied to the transaction by the broker for sales to cover taxes upon vesting of restricted stock units for all employees of Five9, Inc., including the Reporting Person, on the date such sales occurred. The Reporting Person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on May 14, 2025.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $20.47 to $20.73, inclusive. The reporting person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 10, 2024.

The reported sales were to cover taxes upon the vesting of restricted stock units.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $20.18 to $20.42, inclusive. The reporting person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 10, 2024.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $20.10 to $20.60, inclusive. The reporting person undertakes to provide Five9, Inc., any security holder of Five9, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.